I always find it kind of dubious when people selling this kind of thing make a big deal about someone being able to get it through a metal detector undetected. In terms of who they're advertising to, I mean...

The world's best attention-getter! Would-be assailants are going to pull a U-turn when they see you pull out these Blast Knuckles. Aiming is just as easy as punching, and one tap delivers a massive 950,000 volt payload, excellent for disabling or warding off an attacker. The unique, patented design is comfortable to hold, easy to grip and fits in almost any hand. Your self defense budget just got a bump... get these shockers here for LESS!